Oxygen budget and associated processes in the regulated Mosel river. Models intercomparison

During summer, channelized sectors of the Mosel and Saar rivers undergo severe oxygen depletion episodes that compromise their ecological value. A programme was launched by the International Commission for the Protection of river Mosel and Saar (ICPMS) in order to identify the causes of this situation. All processes involved in the oxygen budget, including photosynthesis, algal, bacterial, zooplanktonic, zoobenthic respiration and nitrification, were investigated, and oxygen budgets for different seasonal situations were established.

In close connection with these field investigations, three different mathematical models of the ecological functioning of the river system were implemented: the BfG model of the Saar and Mosel Rivers , the ULg Meuse model, adapted to the river Mosel, and the Mosarel model, resulting from the application to the Mosel-Saar river system of the RIVERSTRAHLER modelling approach We here describe the common features and differences in the conception of these models and present a few examples of their results.